JP2008036606A - Method and apparatus for treating soluble cod component-containing water - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a treatment method of soluble COD component-containing water capable of more sufficiently removing a soluble COD component than a case using powdery activated carbon, and a treatment apparatus of soluble COD component-containing water. <P>SOLUTION: After a fine particulate COD component removing material is added to raw water, an inorganic flocculant, an organic flocculant or an organic high-molecular flocculant is added to raw water to subject the raw water to flocculation treatment before the solid-liquid separation of the raw water. A COD component removing material is preferably and electrolyte polymer having a crosslinked structure substantially water insoluble and having an anionic or hydrogen-bondable functional group. These organic fine particles are added as an inverse phase emulsion dispersed in a hydrocarbon liquid-containing liquid. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a method and an apparatus for removing soluble COD components from water containing soluble COD components such as various industrial wastewater, purified water, and irrigation water. Specifically, the present invention relates to a method and apparatus for removing a soluble COD component using a COD component removing material made of organic fine particles.

  I. When the soluble COD component is removed from the soluble COD component-containing water by using an ion exchange resin as a COD component removing material, conventionally, water is usually passed through an ion exchange resin tower packed with an ion exchange resin (for example, JP 2000-317445 A, JP 2001-276825 A).

  As described above, when wastewater treatment is performed by passing water through the ion exchange resin tower, the resin tower may be blocked due to suspended substances in the wastewater.

II. It is well known that powdered activated carbon is added to wastewater for wastewater treatment, and then this powdered activated carbon is agglomerated by a flocculant and settled. (For example, JP-A-6-226011).
JP 2000-317445 A JP 2001-276825 A Japanese Patent Laid-Open No. 6-226011

  It is an object of the present invention to provide a method and an apparatus for treating water containing soluble COD components that can sufficiently remove soluble COD components in the same manner as in the case of using powdered activated carbon or more than that. And

  The method for treating soluble COD component-containing water according to the present invention comprises adding soluble COD component-containing water to a soluble COD component-containing water, followed by solid-liquid separation, thereby dissolving soluble COD component-containing water from soluble COD component-containing water. In the COD component-containing water treatment method for removing components, the COD component removing material is a substantially water-insoluble organic system having a cationic functional group, an anionic functional group, or a functional group having a hydrogen bonding ability. Fine particles, wherein the organic fine particles are added in a state of being dispersed in a hydrocarbon liquid-containing medium or in a state of being diluted by being dispersed in dilution water.

  The apparatus for treating soluble COD component-containing water according to the present invention comprises means for adding a particulate COD component removing material to soluble COD component-containing water, and thereafter, solid-liquid separation means for subjecting this liquid to solid-liquid separation. In the water treatment apparatus containing soluble COD component, the COD component removing material is a substantially water-insoluble organic fine particle having a cationic functional group, an anionic functional group, or hydrogen bonding ability, The organic fine particles are added in a state of being dispersed in a hydrocarbon liquid-containing medium or in a state of being diluted by being dispersed in dilution water.

  As the organic fine particles, an electrolyte polymer having a crosslinked structure is suitable.

  As a result of various studies by the present inventors, when organic fine particles having the ability to remove COD components, such as electrolyte polymers having a crosslinked structure, are added to water containing soluble COD components, the soluble COD components in water Therefore, when the organic fine particles are solid-liquid separated, the soluble COD component is also removed from the water, and the adsorption action of the soluble COD component by the organic fine particles is substantially equal to or higher than that of the powdered activated carbon. It was found.

  The present invention is based on such knowledge, and according to the present invention, the soluble COD component can be sufficiently removed by a simple process similar to the conventional powdered activated carbon addition plus coagulation separation process.

  In the present invention, by adding organic fine particles such as an electrolyte polymer having a crosslinked structure to the water to be treated as a reverse phase emulsion, even if there is a large amount of suspended substances in the liquid to be treated, There is no obstruction trouble that occurs, and it can be processed efficiently. The cationic functional group or anionic functional group of the resin acts on the ionic COD component, and the functional group having the hydrogen bonding ability of the resin acts on the nonionic COD component. It is presumed that adsorption occurs.

  In the present invention, the COD component and the organic fine particles are sufficiently removed from the liquid by solid-liquid separation, preferably by adding an inorganic flocculant, an organic flocculant, or an organic polymer flocculant to perform the flocculent separation. The order of adding the organic fine particles and the flocculant or coagulant is not limited. However, if a flocculant or a coagulant is added before the organic fine particles, the ionic component brought from the inorganic flocculant increases the load on the organic fine particles and the like, which may prevent efficient treatment. In some cases, it is preferable to add a flocculant or a coagulant first, and then add organic fine particles and the like.

  In the present invention, since the crosslinked polyelectrolyte gel is added as substantially water-insoluble organic fine particles, the COD component diffuses between the molecules of the crosslinked polymer. It can function effectively to the inside of the gel. Moreover, by making it an O / W (reverse phase) emulsion, it is possible to prevent the gel-like organic fine particles from adhering to and coalescing with each other and to maintain the product stability. .

  Hereinafter, the present invention will be described in more detail.

  In the present invention, the organic fine particles are added to the soluble COD component-containing water, and then solid-liquid separation is performed to remove the soluble COD component from the soluble COD component-containing water. As this solid-liquid separation, it is preferable to add an inorganic flocculant, an organic flocculant, or an organic polymer flocculant to cause agglomeration to separate the produced flocs. However, as solid-liquid separation, solid-liquid separation that does not use a flocculant or a coagulant, for example, separation operations such as flotation separation, centrifugation, and filtration may be employed.

  Hereinafter, the soluble COD component-containing water, the organic fine particles, the flocculant and the coagulant, the device form, and the like will be described in detail.

1) Water containing soluble COD components Water containing soluble COD components to be treated by the method and apparatus of the present invention is industrial wastewater discharged from printing factories, semiconductor factories, food factories, paper / pulp factories, chemical factories, etc. Examples include, but are not limited to, treated water from human waste treatment plants and sewage treatment plants, or purified water and irrigation water.

  Examples of soluble COD components include naturally occurring substances such as saccharides and proteins, surfactants, industrial raw materials and scientific substances, food-derived substances, and decomposition products thereof. It is not limited to. The soluble COD component is not limited to ionic properties such as anionic property, cationic property, and nonionic property.

  The molecular weight of the soluble COD component is not particularly limited, but is generally about several tens to several millions, particularly about several hundreds to several hundreds of thousands.

  The present invention is suitable for application when the concentration of the soluble COD component in the water to be treated is about 10 to 5000 mg / L, particularly about 20 to 1000 mg / L.

2) Organic fine particles Examples of the cationic functional groups of the organic fine particles include primary amines, secondary amines, tertiary amines, and functional groups such as acid salts and quaternary ammonium groups thereof. Examples of the anionic functional group include a carboxyl group, a sulfone group, a sulfuric acid group, a phosphonic acid group, and a functional group selected from alkali metal salts and alkaline earth metal salts thereof. The functional group having a hydrogen bonding ability includes a part of the above-described groups such as a carboxyl group, but also includes nonionic groups such as a hydroxyl group, an ether group, an amide group, and an ether group.

  As the organic fine particles, an electrolyte polymer having a crosslinked structure is suitable. Examples of the electrolyte polymer are shown below, but are not limited thereto.

  As organic fine particles, as cross-linked structural monomer units, if anionic, acrylic acid, methacrylic acid, maleic acid, itaconic acid, vinyl sulfonic acid, 2-acrylamido-2-methylpropane sulfonic acid, styrene sulfonic acid, etc. And anionic monomers such as alkali metal salts thereof. Nonionic monomers include nonionic monomers such as poly (meth) acrylamide, N isopropylacrylamide, N methyl (NN dimethyl) acrylamide, acrylonitrile, styrene, methyl or ethyl (meth) acrylate. If it is a cationic type, cationic monomers such as dimethylaminoethyl (meth) acrylate or its quaternary ammonium salt, dimethylaminopropyl (meth) acrylamide or its quaternary ammonium salt, diallyldimethylammonium chloride and the like can be mentioned. These homopolymers or copolymers obtained by combining the above monomers are the basis of the electrolyte polymer. In order to prevent substantial dissolution in water, in addition to the above monomers, divinyl monomers such as methylenebisacrylamide and divinylbenzene are emulsion-polymerized as a crosslinking agent. The amount of divinyl monomer is required to be 0.0001 to 0.1 mol% with respect to the total monomer, and the amount of swelling of the polymer fine particles, that is, the particle diameter in water can be adjusted by this amount.

  In the present invention, the substantially water-insoluble organic fine particles are added to the water to be treated as a reverse phase emulsion.

  As this reverse phase emulsion, those containing the organic fine particles (P), water (W), hydrocarbon liquid (HC), and surfactant (S) are preferable. The ratio of these components P, W, HC, S is P: W: HC: S = 20-50: 20-40: 20-40: 2-20 by weight ratio (%), and the total of P and W The amount is preferably 40 to 80% by weight relative to the total weight.

  As this hydrocarbon liquid, an aliphatic hydrocarbon liquid is suitable, and specific examples include isoparaffins such as isohexane, n-hexane, kerosene, and mineral oil, but are not limited thereto. .

  Moreover, as surfactant, the polyoxyethylene ether of higher aliphatic (C10-20) alcohol of HLB7-10, or the polyoxyethylene ester of higher fatty acid (C10-22) is suitable, for example. Examples of the former include polyoxyethylene (EO addition mole number = 3 to 10) ethers such as lauryl alcohol, cetyl alcohol, stearyl alcohol, and oleyl alcohol. Examples of the latter include polyoxyethylene (EO addition mole number = 3 to 10) esters such as lauric acid, palmitic acid, stearic acid, and oleic acid. However, the surfactant is not limited to these.

[Average particle size]
The average particle diameter of the organic fine particles is preferably 200 μm or less, particularly 1 to 100 μm, and particularly preferably 1 to 10 μm. When the particle size is small, the specific surface area is increased and the reaction efficiency is improved.

  The particle size is measured by a particle size distribution measuring apparatus such as a normal scattered light method or a transmitted light method.

[Ionic]
In the present invention, the ionicity of the organic fine particles may be selected according to the ionicity of the soluble COD component in the water to be treated. The usual soluble COD component is anionic or nonionic. In such a case, it is desirable to apply organic fine particles having a cationic functional group.

[Form of organic fine particles upon addition]
The organic fine particles are added to the water to be treated as the above-mentioned reversed phase emulsion or diluted in water for dilution.

  In order to add the organic fine particle-containing emulsion to the water to be treated, for example, an emulsion stored in a tank can be added using a general liquid feed pump. In addition, you may disperse and add in liquid media, such as water, just before addition.

[Location of organic fine particles]
There is no particular limitation on the place where the organic fine particles are added. Lines may be injected into the pipe of the water to be treated, or they may be added to a reaction vessel equipped with some kind of stirring device.

[Addition rate of organic fine particles]
The addition rate of the organic fine particles varies depending on the solubility and properties of the soluble COD component in the water to be treated, but is preferably about 0.1 to 5 g / L, particularly about 0.5 to 3 g / L in terms of solid content. .

3) Inorganic flocculant, organic flocculant, organic polymer flocculant [Type and amount of inorganic flocculant]
There is no limitation in particular in the kind of inorganic flocculant. A sulfuric acid band, polyaluminum chloride, ferric chloride, ferrous sulfate and the like can be arbitrarily selected.

  There is no limitation in particular in the addition amount of an inorganic flocculant. Although it varies depending on the soluble COD component concentration and other properties of the water to be treated, the solid content is generally 500 to 5000 mg / L.

[Type and amount of organic coagulant]
There is no particular limitation on the type of organic coagulant. Examples thereof include cationic organic polymers usually used in water treatment, such as polyethyleneimine, diallyldimethylammonium chloride, ethylenediamine epichlorohydride polycondensate, and polyalkylene polyamine.

  There is no particular limitation on the amount of organic coagulant added. Although it changes according to the property of the liquid to be treated, it is generally 1 to 100 mg / L in solid content.

[Organic polymer flocculant]
There is no particular limitation on the type of organic polymer flocculant. Any polymer flocculant usually used in water treatment can be used. For example, poly (meth) acrylic acid, a copolymer of (meth) acrylic acid and (meth) acrylamide, and alkali metal salts thereof may be used as long as they are anionic. If it is nonionic, poly (meth) acrylamide etc. are mentioned. In the case of a cationic system, a homopolymer composed of a cationic monomer such as dimethylaminoethyl (meth) acrylate or a quaternary ammonium salt thereof, dimethylaminopropyl (meth) acrylamide or a quaternary ammonium salt thereof, or a copolymer with these cationic monomers. Examples thereof include a copolymer with a polymerizable nonionic monomer.

  There is no limitation in particular in the addition amount of an organic polymer flocculant. Although it changes according to the property of the liquid to be treated, it is generally 1 to 100 mg / L in solid content.

[Addition order of flocculant or coagulant]
First, it is preferable that organic fine particles are added to the water to be treated and further contacted by stirring, and then the flocculant or coagulant is added and further reacted by stirring. The order of addition of the following a, b, or c may be used.

  a: An inorganic flocculant is added and reacted, then organic fine particles are added and reacted, and an organic polymer flocculant is added after pH adjustment.

  b: After organic fine particles are added and reacted well, an inorganic flocculant and an organic flocculant are added to adjust pH, and then an organic polymer flocculant is added.

c: An inorganic flocculant is added and reacted, then organic fine particles are added and reacted, and an organic polymer flocculant is added after pH adjustment.

[Method of adding flocculant or coagulant]
Similar to the operation in normal waste water treatment, a fixed amount may be added according to the amount of water using a liquid feed pump. However, the equipment for addition is not limited to this.

[Combination with other drugs]
You may use together with a disinfectant, a deodorant, an antifoamer, an anticorrosive, etc. as needed.

4) Other Embodiments In the present invention, solid-liquid separation other than solid-liquid separation using a flocculant or a coagulant may be employed as solid-liquid separation after adding organic fine particles.

  In addition to the treatment according to the present invention, if necessary, ultraviolet irradiation, ozone treatment, membrane treatment, biological treatment, etc. may be used in combination, and these treatments are performed either before, after or during the treatment of the present invention. It may be broken.

  In addition, an effect can be confirmed by performing normal CODmn and CODcr measurement of treated water. If necessary, a pretreatment such as filtration may be performed before the measurement.

5) Example of the apparatus of the present invention FIG. 1 is a system diagram showing an example of a treatment apparatus for water containing soluble COD components suitable for carrying out the method of the present invention. The raw water (soluble COD component-containing water) is introduced into the mixing tank 1, where the organic fine particle-containing reversed-phase emulsion is added, and is preferably stirred slowly with a stirrer. The liquid in the mixing tank 1 is then sent to a coagulation tank where it is added with an inorganic coagulant, an organic coagulant or an organic polymer coagulant and is preferably stirred slowly.

  The liquid in the flocculation tank 2 is sent to the precipitation tank 3, where it is separated into solid and liquid and treated water (supernatant water), and the treated water is taken out of the system.

  In addition, an inorganic flocculant and an organic polymer flocculant or an organic flocculant may be added to the flocculation tank 2, and a floc growth tank is provided between the flocculation tank 2 and the precipitation tank 3. An inorganic flocculant may be added, and an organic polymer flocculant or an organic flocculant may be added to the floc growth tank.

  Hereinafter, examples and comparative examples will be described. In this example and comparative example, a test wastewater using the reagent “starch” as a model COD component was used as raw water. As the starch reagent, a special grade reagent manufactured by Kishida Chemical was used. The degree of anionization by colloidal equivalent measurement was −0.15 mep / g, which was slightly anionic.

  The test drainage adjustment method is as follows. First, a 5 wt% aqueous starch solution dissolved by heating with a hot plate stirrer was prepared, and 83 ml of the aqueous starch solution was added to 9917 ml of pure water to obtain a 414 mg / l aqueous starch solution. The CODmn of this aqueous solution was 309 mg / l measured.

  As a water-insoluble organic fine particle reversed phase emulsion liquid, a crosslinked gel fine particle (average particle size of 15 μm) of dimethylaminoethyl acrylate methyl chloride quaternary compound / acrylamide = 60/40 (mol%) copolymer is used as the organic fine particle. What was included was used.

  The manufacturing procedure of this gel is as follows.

  Prepare a 1L 4-neck separable flask equipped with a stirrer, Dimroth condenser, nitrogen inlet, and thermometer, and add 123g of kerosene mixed with 48g of higher alcohol polyoxyethylene ether with HLB = 9.5 under nitrogen atmosphere. Place in flask. While stirring vigorously in a nitrogen atmosphere, a mixture of 178 g of methyl chloride quaternized product of dimethylaminoethyl acrylate (65%), 28 g of acrylamide, 0.01 g of methylenebisacrylamide and 82 of water is slowly put into the flask. The inside of the flask is maintained at 50 ° C., and 0.65 g of a 10% solution of azobisisobutyronitrile in acetone is added as an initiator, and polymerization is carried out while stirring at 50 ° C. for 8 hours in a nitrogen atmosphere. The reaction product was an insoluble fine particle gel that did not dissolve even when placed in water.

  The composition of the gel dispersion was 31% by weight of polymer, 31% by weight of water, 27% by weight of kerosene, and 11% by weight of surfactant. The components of the gel are 50% by weight of polymer and 50% by weight of water.

  For convenience of explanation, Comparative Examples 1 and 2 using powdered activated carbon added or a water-soluble polymer will be described first.

Comparative Example 1
In Comparative Example 1, powdered activated carbon having a specific gravity of 0.35 Kg / L was used.

  Six 500 mL beakers containing 500 mL of the test waste water were prepared and installed in a six-unit jar tester.

  Powder of 0, 0.025, 0.05, 0.1, 0.3, 0.5, 1.0 g so that the addition rate is 0, 50, 100, 200, 600, 1000, 2000 mg / L Activated carbon was added as a powder, and was first dispersed in the liquid with a spatula.

  Immediately, the mixture was stirred with a jar tester at 150 rpm for 30 minutes.

  Subsequently, 3000 mg / L of a sulfuric acid band as an inorganic flocculant was added to each solution, and the mixture was similarly stirred at 150 rpm for 60 seconds.

  Subsequently, the pH was adjusted to approximately 7, centrifuged at 3000 rpm for 10 minutes, and the CODmn of the supernatant was measured.

  In addition, COD measurement of raw | natural water measured by performing the same operation as the above, without adding activated carbon.

  The results are shown in FIG.

Comparative Example 2
The same operation as in Comparative Example 1 was conducted except that instead of powdered activated carbon, a methylaminoethyl acrylate methyl chloride quaternary compound / acrylamide 60/40 (mol%) copolymer was used as the water-soluble polymer.

Example 1
It carried out by the same operation as the comparative example 1 except having used the gel as an organic type fine particle containing emulsion instead of the powdered activated carbon of the said comparative example 1. FIG.

  Also in Example 1, the addition rate of the organic fine particles was set to 0, 50, 100, 200, 600, 1000, and 2000 mg / L as in Comparative Example 1.

  The COD measurement result of treated water is shown in FIG.

  As shown in FIG. 2, according to Example 1, a better COD removal effect can be obtained as compared with Comparative Examples 1 and 2. Even if an ordinary water-soluble polymer is adsorbed with starch as a COD component, it remains dissolved and cannot be precipitated and separated from water, so it is considered that the COD corresponding to the amount of polymer added has increased. .

It is a flowchart of an Example. It is a graph which shows the COD measurement result of an Example and a comparative example.

Explanation of symbols

1 Mixing tank 2 Coagulation tank 3 Precipitation tank

Claims (7)

In the method for treating COD component-containing water in which the soluble COD component-containing water is removed from the soluble COD component-containing water by adding a particulate COD component removing material to the soluble COD component-containing water, followed by solid-liquid separation.
The COD component removing material is a substantially water-insoluble organic fine particle having a cationic functional group, an anionic functional group, or a functional group having hydrogen bonding ability,
A method for treating water containing soluble COD components, wherein the organic fine particles are added in a state of being dispersed in a hydrocarbon liquid-containing medium or in a state of being dispersed and diluted in dilution water.   2. The method for treating COD component-containing water according to claim 1, wherein an average particle diameter of the dispersed organic fine particles is 200 μm or less.   The method for treating water containing soluble COD components according to claim 1 or 2, wherein the hydrocarbon liquid is an aliphatic hydrocarbon liquid.   The method for treating soluble COD-containing water according to any one of claims 1 to 3, wherein the medium is a mixture of water and a hydrocarbon liquid.   5. The method for treating COD component-containing water according to any one of claims 1 to 4, wherein the organic fine particles are an electrolyte polymer having a crosslinked structure.   6. The solid-liquid separation according to claim 1, wherein the solid-liquid separation is performed by adding at least one of an inorganic flocculant, an organic flocculant, and an organic polymer flocculant to cause aggregation, and separating the generated floc flocs. A method for treating water containing soluble COD components, comprising: In a treatment apparatus for soluble COD component-containing water having means for adding a particulate COD component removing material to soluble COD component-containing water and then solid-liquid separation means for subjecting this liquid to solid-liquid separation treatment,
The COD component removing material is a substantially water-insoluble organic fine particle having a cationic functional group, an anionic functional group, or hydrogen bonding ability,
An apparatus for treating water containing a soluble COD component, wherein the organic fine particles are added in a state of being dispersed in a hydrocarbon liquid-containing medium or in a state of being diluted by being dispersed in dilution water.

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